Counterbalancing means for engraving and copying machines



0d. 21, 1941. zw c 2,260,157

FOUNTERBALANCING MEANS-FOR ENGRAVING AND COPYING MACHINES Original Filed March 28, 1936 III INVENTOR Kurfl Zwick W & W

A'ITORNEYS Patented Oct. 21, 1941 COUNTERBALANCING MEANS FOR ENGRAV- ING.AND COPYING MACHINES Kurt Zwick, Munich, Germany, assignor to Friedrich Deckel, Munich-Prinz Luwigshohe,

Bavaria, Germany Original application March 28, 1936, Serial No. 71,483. Divided and this application March 14, 1939, Serial No. 261,806. In Germany July 24,

4 Claims.

This invention relates to counterbalancing means useful, for example, in engraving and copying machines and the like, or in any machine tools where upwardly and downwardly Ample counterbalancing means for counterbalancing all or any desired portion of the weight of upwardly and downwardly movable parts of machines of various kinds, such as engraving and copying machines.

Another object of the invention is the provision of counterbalancing means so designed that the mass inertia of the counterbalancing system will aid in damping vertical vibrations of the parts supported by the counterbalancing system.

To these and other ends the invention resides in certain improvements and combinations of parts, all as will be hereinafter more fully described, the novel features being pointed out in the claims at the end of the specification.

In the drawing:

Fig. 1 is a side elevation, somewhat diagrammatic, of one form of engraving and copying machine with one embodiment of the present counterbalancing means applied thereto, and

Fig. 2 is a diagrammatic plan view of the parts shown in Fig. 1.

The same reference numerals throughout the several views indicate the same parts.

The present application is a division of my United States patent application, Serial No. 202,568, filed April 16, 1938, for Counterbalancing means for engraving and copying machines, which application, in turn, is a division of my parent United States patent application, Serial No. 71,483, filed March 28, 1936, for Engraving and copying machine. Certain subjectv matter disclosed but not claimed herein is claimed in one or the other of said two applications, or in other divisions thereof.

As a convenient example of one type of ma-' chine with which the present invention may be used, there is illustrated in Figs. 1 and 2 an engraving andcopying machine having a main frame having a horizontal pivot 46 on which is pivoted a carrier 41. The carrier has an approximately vertical pivot 25 which forms the main pivot-of a lazytongs pantograph linkage made up of the members 2|, 22, 23, and 24 pivoted to each other in known manner, the part 24 being adjustable to various positions along the members 22 and 23.

The linkage member 24 has a downwardly pro ecting pin 39 which is pivotally connected to the member 40 which is capable of being clamped in various positions along a bar 4|, which may be secured in any desired position lengthwise of a parallel motion beam 30 mounted for movement universally in all directions and guided so that each position is parallel tq each other position of the beam. This movement of translationof the beam 30 in all directions without any movernent of rotation, may be secured by mounting it in any suitable known manner, or by providing it with a parallelogram linkage, such as the bars 55 and 56, pivoted to the beam 30 near opposite ends, which bars are pivoted in turn to bars 51 and 58, the other ends of which are pivoted to a vertically slidable member 59, mounted for movement along a vertical guideway 62 on the frame 45. A bar 66 connects the joint between the bars 55 and 51 to the joint between the bars 56 and 58, in known parallelogram linkage manner. Thus thebeam 30 is mounted for parallel motion or motion of translation in all d rections, for it may move horizontally in any direction (remaining always parallel to itself) by iiexure of the parallelogram linkage on which it ismounted, and it may move vertically by moving the member 59 up ordown the guideway 62.

According to the present invention, the weight of the vertical slide 59 and the parallelogram linkage and beam 30 and all, parts supported thereby, is counterbalanced in a manner producmg a substantially constant upward thrust on the slide 59 at all elevations thereof, and preferably also in a manner which tends to damp vertical vibrations of the member 59 and parts supported thereby. In the form here shown,

there is a counterweight :64 connected to the member 59 by a cord or band 65 passing upwardly from the counterweight to a pulley 66 mounted on the machine frame, and thence downward- 1y from this pulley to a suitable connection with the slide 59. Another pulley 61 is mounted on the machine frame below the counterweight 64, and a cord or band. 68 of adjustable length passes downwardly from the counterweight 64, around the pulley 61, and up to a suitable connection with the slide 59. When the cord 68 is adjusted to be reasonably tight, the mass inertia of the counterweight 64 helps to damp or attenuate the vertical vibrations of the various parts carried by the slide 59, for the tendency of those-parts to vibrate downwardly would produce stress in the band or cord 65, while a y tendency to vibrate upwardly, would produce stress in the band or cord 68. The inertia of the mass 64 offers resistance to both upward and downward vibrations, thus resulting in a construction unusually free from such vibrations.

An arm '10 may be pivoted'at one end, by means of a vertical pivot, to the beam 30. An other arm II is pivoted at one end, by means of a vertical pivot, to the end of the arm 10 remote from the beam 30, and the free end of the arm M carries a socket 12 in which may be placed either a tracing stylus or a cutting tool, as required. A tool or stylus I3 is so mounted as to be vertically slidable through the socket 12. The upper end of the tool or stylus is pivotally connected at H, as by means of a universal joint, to a member 15 fixed to the lazytongs linkage at a point which is in the same vertical plane with the vertical pivot and with the pivot 39. A handle 16 may be provided for convenience in guiding the stylus over a pattern mounted on a pattern table 21 supported from the machine frame 45.

The beam carries two or more holders and 36, adapted to receive interchangeably either a cutting tool or a tracing stylus. A tool or stylus mounted in the holder 35 may operate over work or a pattern on the table 31 supported on the frame 45. Likewise a tool or stylus mounted in the holder 36 may operate over work or a. pattern mounted on the table 38 supported on the frame 45. A rotary cutting tool mounted in the holder 35 is indicated at 4 9 in Fig. 1, for purposes of illustration.

Assuming that a tracing stylus rather than a cutting tool is mounted at the point 13 and that a cutting tool 49 is mounted in the holder 35,

the tracing .stylus is moved over the pattern on the table 21 by operation of the handle I6. The horizontal components of movement of the stylus will move the lazytongs pantograph linkage and, by movement of this linkage transmitted through the pivot, will cause corresponding movement on a reduced scale of the beam 30 and of the cutting tool 49 mounted thereon. The vertical components of movement of the stylus 13 (which is always guided vertically in the holder 12) will tilt the lazytongs pantograph linkage upwardly or downwardly about its horizontal pivot Ali, and this upward or downward movement will be transmitted, in the proper reduced ratio, through the connecting members 39 and 40 to the beam 30, causing proper upward and downward movements of the beam by sliding the slide member 59 up Or down its guideway 62. Thus the work operated upon by the tool 49 will be an accurate reproduction, on 'a smaller scale, of the pattern ternately in the band or cord 65 and the band or cord 88 connected to the counterweight N. The

inertia of the counterweight mass will resist the vertical components of vibration so that the vibration will be damped and greatly diminished.

While one embodiment of the invention has been disclosed, it is to be understood that the inventive idea may be carried out in a number of ways. This application is therefore not to be limited to the precise details described, but is intended to cover all variations and modifications thereof falling within the spirit of the invention or the scope of the appended claims.

I claim: I

1. An engraving or copyin machine comprising'a frame, a substantially vertical guideway on said frame, a'slide movable substantially vertically along said guideway, means supported from said slide for holding a cutting tool, counterweight means of substantial mass, pulley means above said counterweight means, connecting means passing upwardly from said counterweight means to said pulley means and from said pulley means to said vertically movable slide so that the mass of said counterweight means counterbalances at least in part the weight of said slideand of the parts carried thereby, other pulley means below said counterweight means, and connecting means passing downwardly from said counterweight means to said other pulley means and upwardly from said other pulley means to said slide, said last named connecting meansb'eing under tension so that the mass of said counterweight means will tend to damp upward and downward vibration of said slide.

movement relative thereto, a beam mounted on said slide member, means guiding said beam for beam 30. Those components of vibration which aresubstantially vertical will produce stress alsubstantially horizontal movement of translation while restraining it against movement of rotation relative to said slide member, holding means on said beam for holding a cutting tool, pulley means mounted on said frame means, a weight having a substantial mass, a flexible element extending upwardly from said weight to said pulley means and partially around said pulley means and thence downwardly to said slide member, bther pulley means mounted on said frame means below aid weight, and a flexible element connected to said weight and extending downwardly therefrom to said other pulley means and thence upwardly to said slide member so that mass inertia of said weighttends to retard sudden downward movement of that part of said flexible element extending downwardly therefrom and thus tends to damp vertical vibrations of said slide member by resisting sudden upward movement thereof.

I 3. An engraving or copying machine comprising a frame, a substantially vertical guideway on said frame, a slide movable substantially vertically along said guideway, means supported from said slidefor holding a cutting tool, counterweight means of substantial mass operatively connected to said slide to counterbalance at least in part the weight of said slide and of the parts carried thereby, and tension means connecting said counterweight means to said slide to tend to move said counterweight means downwardly otherwise than by gravity when said slide vibrates upwardly, so that the mass inertia oi'said counterweight means tends to damp vertical vibrations of said slide, said tension means being in the form of an elongated flexible member.

4. An engraving or copying machinecomprising a frame, a substantially vertical guideway on said frame, a slide movable substantially vertically along said guideway, means supported from said slide for holding a cutting tool, counterweight means of substantial mass operatively connected to said slide to counterbalance at least in part the weight of said slide and of the parts carried thereby, and tension'means connecting said counterweight means to said slide to tend to move said counterweight means downwardly otherwise than by gravity when said slide vibrates upwardly, so that the mas inertia of said counterweight means tends to damp vertical vibrations of said slide, said tension means being in the form of a band maintained constantly under tension during normal operation.

KURT .ZWICK.

CERTIFICATE OF CORRECTION. Patent No. 2,260,157. October 21, 19in.

KURT ZWICK.

It is hereby certified that error appears in the above numbered patent requiring correction as follows; In the grant, line 2, and in the heading vto the printed specification, line 5, residence of assignee, for "Munich- Prinz Luwigshohe" read --Nunich-Prinz Ludwigshohe; page 2, second column, line 55, claim 1, for "vibration" read -vibrations--; and that the said Letters Patent should he read with this correction therein that the same may, conform to the record of the case in the Patent Office.

Signed and sealed this 25th day of November, A. D. 19m.

Henry Van Arsdale, (Seal) Acting Commissioner of Patents. 

